Organochlorine pesticide in fresh and pasteurized cow’s milk from Kampala markets

► Levels of OC pesticides have been determined in cow’s fresh and pasteurized milk samples in Kampala. ► Levels found were higher in raw milk than in pasteurized milk. ► Results proved the efficient role of heat treatment on the degradation of OC pesticides. ► Pasteurized milk is safer than raw milk. Fresh and pasteurized milk samples from Kampala markets were analyzed for organochlorine pesticides using a gas chromatograph equipped with an electron capture detector. Five organochlorine pesticides, namely; aldrin, dieldrin, endosulfan, lindane, DDT and its metabolites were detected in the milk samples and confirmed with a gas chromatograph equipped with a mass spectrometer [GC-MS]. The mean values are expressed in mgkg−1 milk fat (mf) basis. The mean concentration in the fresh milk (n=54) were: 0.026±0.003mgkg−1 mf; 0.002±0.0003mgkg−1, below the detection limit; 0.007±0.003mgkg−1, 0.009±0.002mgkg−1 milk fat for lindane, endosulfan dieldrin and aldrin, respectively. The mean concentrations of p,p′-DDE; p,p′-DDT and o,p′-DDT were 0.009±0.002mgkg−1; 0.033±0.007mgkg−1 and 0.008±0.001mgkg−1 mf, respectively in the fresh milk samples. In the pasteurized milk samples (n=47), the mean concentrations recorded were: 0.008±0.003mgkg−1, 0.025±0.004mgkg−1, and 0.007±0.001mgkg−1, respectively for p,p′-DDE; p,p′-DDT and o,p′-DDT. Alpha and beta-endosulfan recorded the concentration below the detection limit and the mean of 0.022±0.001mgkg−1 mf, 0.005±0.002mgkg−1 mf, and 0.006±0.0002mgkg−1 mf, respectively for lindane, dieldrin and aldrin. Although, most of the residues detected were above the residue limits set by the FAO/WHO (2008), bioaccumulation of these residues is likely to pose health risks to the consumers of milk in Uganda.